A fuel cell is being developed as a replacement of a fossil fuel that is not eco-friendly. The fuel cell is a generating device for directly converting chemical energy into electric energy. A hydrogen-including fuel and an oxygen-including air are continuously supplied to the fuel cell, in which the hydrogen and the oxygen are electrochemically reacted to each other. The fuel cell directly converts an energy difference between before the reaction and after the reaction into electric energy. The fuel cell is continuously provided with a fuel and oxygen thereby to continuously generate electric energy.
The fuel cell includes a phosphoric acid fuel cell, an alkaline fuel cell, a proton exchange membrane fuel cell, a molten carbonate fuel cell, a solid oxide fuel cell, a direct methanol fuel cell, etc. Said fuel cells are operated by the same principle, and are classified according to a kind of a used fuel, a driving temperature, a catalyst, etc.
Also, the fuel cell is being developed to be applied variously as a domestic fuel cell for supplying electricity to a home, a fuel cell used in an electricity car, a fuel cell used in a mobile terminal or a notebook computer, a fuel cell movable at home and supplying electricity, etc.
Especially, a fuel cell for operating home electronics or other electric devices by being moved at home or at an outdoors has to be minimized in order to be conveniently portable, and has to maximize an output of electric energy under a state that the size thereof is limited. Also, a stability of the fuel cell has to be obtained.